Blowpipe



F. S. AUSTIN Dec. 19, 1933.

BLOWPIPE Filed May 51, 1930 Patented Dec. 19, 1933 UNITED STATES PATENT OFFICE Application May 31, 1930. Serial No. 457,959

6 Claims.

This invention relates to blowpipes and while applicable to other uses, is particularly adapted for such purposes as the cleaning of molds and for brazing and welding.

One of the objects of the invention is to provide for blowpipes acooperating construction of tip, head and connector whereby the tip may be secured quickly and conveniently to the head with the practical elimination of leakage be- IO itWeen the parts. A still further object of theinvention is to provide forblowpipes means for effecting an efficient mixture of oxygen and combustible gas in the head bodies thereof.

I realize the foregoing objects in and through the construction and arrangement of parts shown in the drawing, wherein Fig. 1 represents a side elevation of a blowpipe embodying my invention; Fig. 2 a central longitudinal sectional view through the body and head of said blowpipe; Fig. 3 a detail in section corresponding to the line 3-3 of Fig. 1; and Figs. 4, 5 and 6 are details in section corresponding respectively to. the lines 44, 5--5 and 6-6 on Fig. 2.

Describing the various parts by'reference char- 'acters, 1 denotes a valve block, provided with connections 2 and 3 for oxygen and combustible gas, respectively. p f

The oxygen supplied through the connection 2 passes through the block by means of a port 4, the chamber 5 controlled by the valve 6, and the port '7. From the block it passes through the pipe A and through a' port 8 in a block B to a restricted port 9 in a mixing plug C threaded into a central bore provided therefor in the body B.

The combustible gas supplied through the connection 3 passes through the block 1 by means of a port 10, the chamber 11 controlled by the.

valve 12, and the port 13. From the block 1 it passes through the pipe Dand thence through a, port'14 in the block B to an annular chamber 15 provided between the plug C and the surrounding wall of the bore B. From the chamber 15, the gas is delivered by a plurality of ports 16 into the enlarged portion 9 of the bore 9. I prefer to employ at least six of these ports and to arrange them so that the centers of their delivery ends communicate with the bore 9 in a common plane at right angles to said bore. By virtue of this number and arrangement of parts the gas receiving area of the bore 9 is enlarged at the delivery ends of said ports 16, due to the aggregate area of the metal of said bore which has been removed by the intersections of the delivery ends of said ports with said bore; and

this, together with the enlargement of the bore section 9*, contributes toward an eflicient mixture of the oxygen and the combustible gas in the mixing plug C.

It will be noted that the plug C is provided with an annular shoulder C which acts as a stop to limit the insertion of the rear end of the plug into the bore B and that the front of said plug, extending from said shoulder, is frusto-conical, as shownat C the frusto-conical portion 05. being provided with an annular groove C therearound. This frusto-conical portion of the plug fits within a frusto-conical rear enlargement D of a central passage or bore D of the head body D.

The body D is connected to the block B by means of a collar threaded onto the rear of the body D and having a rear extension E adapted to overhang and to receive therewithin the shoulder C. A gland nut F is threaded on the. front end of the block B and has a shoulder F closely surrounding the rear of the body D and engaging the collar E. By setting up the nut F, the rear end of the body D is forced upon the irusto-conical front end of the mixing block C.

At its forward end, the passage D delivers 89 the mixture of gases therein into a chamber D in the front of the head body D through a plurality of restricted ports D It will be noted that the front end of the head proper is provided with an externally convex surface D and with a 86 thread D above such surface.

Cooperating with the head is a tip comprising an inner member G and an outer member H. The inner member G has a cylindrical upper portion and a frusto-conical lower portion. The 9 cylindrical portion is provided with a plurality of wide slots 17, providing passages with the surrounding portion of the outer tip member. The lower ends of these passages communicate with an annular chamber 18 formed between the tip 9 members, whence passages 19 extend in a convergent direction to the delivery end of the tip.

A central bore 20 extends through the inner tip member.

The upper end of-the outer tip member is flared outwardly, as shown at H, forming a frusto-conlcal flange beyond which the upper end of the inner tip member projects. This end fits easily within the lower portion of the chamber D and serves as a guide for assembling the tip to the head.

J denotes a gland nut threaded on the lower end of the head proper and having a shoulder J fitting the outer tip member and provided within such shoulder with an inwardly extending convex surface J engaging the flange H. By setting up the nut J, the flange H will be gripped tightly between the surfaces D and H, with approximately a line contact between each of these surfaces and the flange. This enables me to provide a leak-proof connection between the tip and the head.

Having thus described my invention, what I claim is 1. A blowpipe comprising in combination a head having a chamber extending upwardly thereinto from the bottom thereof and one or more passages for delivering gas to said chamber, the said head having a seating surface extending outwardly and upwardly from the lower end thereof, the said seating surface being outwardly convex, a tip comprising an inner member the upper end of which is adapted to be received within the lower end of said chamber and also comprising an outermember the upper'end of which terminates below the upper end of the inner member and which forms a substantially frusto-conical extension of said outer member, and means for securing the tip to the head, said means serving to press the said extension into close engagement with the outwardly convex seating surface.

2. A blowpipe comprising in combination a head having a chamber extending upwardly thereinto from the bottom thereof and one or more passages for delivering gas to said chamber, the said head having a seating surface extending outwardly and upwardly from the lower end thereof, a tip comprising an inner member the upper end of which is adapted to be received within the lower end of said chamber and also comprising an outer member the upper end of which terminates below the upper end of the inner member and which forms an outwardly flaring extension of said outer member, and means for securing the tip to the head, said means serving to press the said extension into close engagement with the aforesaid seating surface.

3. A blowpipe comprising in combination a head having a chamber extending upwardly thereinto from the bottom thereof and one or more passages for delivering gas to said chamber; the said head having a seating surface extending outwardly and upwardly from the lower end thereof, the said seating surface being outwardly convex, a tip comprising an inner member the upper end of which is adapted to be received within the lower end of said chamber and also comprising an outer member the upper end of which terminates below the upper end of the inner member and which forms a substantially frusto-conical extension of said outer member, and means for securing the tip to the head, said means serving to compress the said extension against the outwardly convex seating surface and to provide substantially a line-contact between the extension and the seat and between the extension and the securing means.

4. A blowpipe comprising in combination a head having a chamber extending upwardly thereinto from the bottom thereof and one or more passages for delivering gas to said chamber, the said head having a seating surface extending outwardly and upwardly from the lower end thereof, a tip comprising an inner member the upper end of which is adapted to be received within the lower end of said chamber and also comprising an outer member the upper end of which terminates below the upper end of the inner member and which provides a substantially frusto-conical extension of said outer member, and means for securing the tip to the head, said means serving to compress the said extension against the seating surface and to provide a substantially line contact between the extension and the seat and between the extension and the securing means.

5. A blowpipe comprising in combination a head having a chamber extending upwardly thereinto from the bottom thereof and one or more passages for delivering gas to said chamber, the lower portion of said head being externally threaded and being provided with a seating surface converging from the bottom of said thread toward the axis of said chamber, the seating surface being outwardly convex, a tip comprising an inner member the upper end of which is adapted to be received within the lower end of said chamber and also comprising an outer member the upper end of which terminates below the upper end of the inner member in an inverted substantially frusto-conical flange, and a gland nut for detachably securing the said tip in place, the said gland nut having a central opening conforming to the outer tip member below the flange and having an internal thread adapted to engage the thread on said head and being provided below the threaded portion thereof with an inwardly extending flange-engaging surface, the said flange-engaging surface being convex, whereby the flange will be clamped between two convex surfaces.

6. A blowpipe comprising in combination a head having a chamber extending upwardly. thereinto from the bottom thereof and one or more passages for delivering gas to said chamber, the lower portion of said head being externally threaded and being provided with a seating surface converging from the bottom of said thread towardthe axis of said chamber, a tip comprising an inner member the upper end of which is adapted to be received within the lower end of said chamber and also comprising an outer member the upper end of which terminates below the upper end of the inner member in an inverted substantially frusto-conical flange, and a gland nut for detachably securing the said tip in place, the said gland nut having a central opening conforming to the outer tip member below the flange and having an internal thread adapted to engagev the thread on said head and being provided below the threaded portion thereof with an inwardly extending flange-engaging surface.

FRANCIS S. AUSTIN. 

